Aim of the study was to isolate and characterize Gram negative bacilli causing urinary tract infections in catheterized patients of either sex and above 19 years of age in intensive care units and to study the antimicrobial sensitivity pattern of the urinary isolates. Total of 100 catheterised patients in Intensive care units were analysed retrospectively and prospectively in a period of 1 year from December 2012 to November 2013 to assess the urinary tract infections caused by indwelling catheter. Of 100 cases, 26 showed catheter associated urinary tract infections. Out of them 11 were E. coli, 5 each for Klebsiella spp and Pseudomonas aeruginosa, 2 were Citrobacter spp, and one case each for Enterobacter spp, Acinetobacter spp, Schwanella spp. Isolates were multi drug resistant and showed sensitivity to Cefoperazone-Sulbactam, Piperacillin-Tazobactam, Carbapenems and Colistin. Infections were more with male sex, prolonged catheterization, old age and diabetes. High incidence of CAUTI was found in the first 2 weeks of catheterization. The antimicrobial susceptibility pattern confirmed that most of the urinary isolates in our environment are resistant to the commonly used antibiotics.
Trang 1Original Research Article https://doi.org/10.20546/ijcmas.2019.801.130
Microbiological Profile and Antibiogram of Gram Negative Bacilli
Isolated from Catheter Associated Urinary Tract Infection (CAUTI) in
Intensive Care Units of a Tertiary Care Hospital
Anupama Bahuleyan 1 , K.H Harshan 2 * and Geeta Bhai 3
1 ESI Hospital, Peroorkada, India 2
Department of Microbiology, MZMC, Adoor, India 3
Department of Microbiology, SGMC&RF, Venjaramoodu, India
*Corresponding author
A B S T R A C T
Introduction
Catheter associated urinary tract infection is a
leading cause of morbidity and mortality in
hospitalized patients When left in place for
too long or used inappropriately, it is a hazard
to the very patient that it is designed to
protect.17, 15
According to 2009 International practice
guidelines of Infectious Diseases Society of
America, CA-UTI in patients with indwelling urethral, indwelling suprapubic, or intermittent catheterization is defined by the presence of symptoms or signs compatible with UTI with
no other identified source of infection along with ≥ 103colony forming units (cfu/ml) of ≥ 1 bacterial species in a single catheter urine specimen or in a mid stream voided urine specimen from a patient whose urethral, suprapubic or condom catheter has been removed within the previous 48 hours.10
International Journal of Current Microbiology and Applied Sciences
ISSN: 2319-7706 Volume 8 Number 01 (2019)
Journal homepage: http://www.ijcmas.com
Aim of the study was to isolate and characterize Gram negative bacilli causing urinary tract infections in catheterized patients of either sex and above 19 years of age in intensive care units and to study the antimicrobial sensitivity pattern of the urinary isolates Total of
100 catheterised patients in Intensive care units were analysed retrospectively and prospectively in a period of 1 year from December 2012 to November 2013 to assess the urinary tract infections caused by indwelling catheter Of 100 cases, 26 showed catheter
associated urinary tract infections Out of them 11 were E coli, 5 each for Klebsiella spp and Pseudomonas aeruginosa, 2 were Citrobacter spp, and one case each for Enterobacter spp, Acinetobacter spp, Schwanella spp Isolates were multi drug resistant and showed
sensitivity to Cefoperazone-Sulbactam, Piperacillin-Tazobactam, Carbapenems and Colistin Infections were more with male sex, prolonged catheterization, old age and diabetes High incidence of CAUTI was found in the first 2 weeks of catheterization The antimicrobial susceptibility pattern confirmed that most of the urinary isolates in our environment are resistant to the commonly used antibiotics
K e y w o r d s
Intensive care units
(ICU), Urinary tract
infections (UTI),
Catheter associated
(CA), Multi drug
resistant (MDR)
Accepted:
10 December 2018
Available Online:
10 January 2019
Article Info
Trang 2Patients in the Intensive care units are at high
risk of device associated infection due to
underlying conditions and impaired host
defenses, surgery and invasive medical
procedures6.Indwelling urinary and central
venous catheters are used commonly in the
care of critically ill patients Though important
clinical benefits are provided by both types of
devices, they are also the leading causes of
nosocomial infection in the intensive care
units14
UTI’s were the third most common type of
infection which occurs in ICU’S after
pneumonia and lower respiratory tract
infections UTI’s occurring in ICU’s
comprises 8% to 21% of all nosocomial
infections Because patients in ICU’s require
frequent and careful monitoring of intake and
output and many of them use urinary catheter,
the risk of UTI is significantly higher than in
other patient populations5
Approximately 97% of UTI’s in the ICU are
associated with an indwelling urinary catheter
Because most patients admitted to ICU’s have
complications that are significant and are
sicker than other patients, the effects of
CA-UTI are more critical 5
Patients in the intensive care unit are at a
higher risk of device-associated infection, due
to their impaired host defences, underlying
conditions, surgery, and invasive medical
procedures.7 Central role in the pathogenesis
of CAUTI is played by presence of a biofilm.6
CAUTIs are cause for concern because
catheter-associated bacteriuria comprises a
huge reservoir of resistant pathogens in the
hospital environment 6 and an important goal
of health- care infection prevention
programmes is prevention of infections
attributable to these devices.14
CA-UTI are caused by a variety of pathogens,
which includes Gram negative bacilli like
aeruginosa
Up to 25% of patients who require a urinary catheter ≥ 7 days develop Nosocomial bacteriuria with a daily risk of 5%15 Bacteriuria develops at an average rate of 3%
to 10% per day of catheterization.4Many of these microorganisms belong to the patient’s endogenous bowel flora but they can also be acquired from other patients or hospital personnel by cross-contamination or by exposure to contaminated solutions or non-sterile equipment.12
CAUTIs are a cause of concern because catheter- associated bacteriuria comprises a huge reservoir of resistant pathogens in the hospital environment.7 The epidemiology, frequency, microbiological spectrum and antimicrobial resistance patterns of microorganisms causing Device-Associated Infections vary among institutions and can change yearly Multidrug resistant pathogen infection are on the rise, which further complicates the management of these infections.6 Documented phenomena include the emergence of extended spectrum beta
lactamase producing E coli 4
In healthy patients CA-UTI is often asymptomatic and is likely to resolve spontaneously with removal of the catheter Infection persists occasionally and leads to complications such as prostatitis, epididymitis, cystitis, pyelonephritis and gram negative bacteremia particularly in high risk patients The last complication is serious since it is associated with a significant mortality but fortunately occurs in less than 1% of catheterized patient’s.12
CA-UTI is the second most common cause of nosocomial blood stream infection.13
The vast majority of nosocomial UTIs occur
in patients whose urinary tracts are currently
Trang 3or recently catheterized The duration of
catheterization is the most important risk
factor for the development of CA-bacteriuria
Other risk factors for CA-bacteriuria include
the lack of systemic antimicrobial therapy,
female sex, meatal colonization with
uropathogens, microbial colonization of the
drainage bag, catheter insertion outside the
operating room, catheter care violations like
improper position of the drainage tube (above
the level of the bladder or sagging below the
level of collection bag), absence of use of a
drip chamber, rapidly fatal underlying illness,
older age, diabetes and elevated serum
creatinine at the time of catheterization.9, 15
Most episodes of bacteriuria in short term
catheterized patients are caused by single
organisms, mostly E coli and Klebsiella spp
E coli cause most of the infections
Biofilm formation by uropathogens like
Klebsilla pneumoniae is favoured by presence
of indwelling urinary catheters by providing
an inert surface for the attachment of bacterial
adhesins, which enhances colonization by
microbes and helps in the development of
biofilm Attachment of biofilms to catheters is
initiated by adhesins, for example, fimbriae,
located on the bacterial surface The best
understood K pneumoniae fimbrial types that
are also the most frequently encoded are
fimbriae type 1 fimbriae and type 3 fimbriae
Type 1 fimbriae are encoded by the majority
of Enterobactericeae and it was established
that type 1 fimbriae are essential for the ability
of K pneumoniae to cause urinary tract
infections.8
The virulence of Pseudomonas aeruginosa is
multifactorial and the cell associated factors
responsible for its virulence are alginate,
lipopolysaccharide, flagellum, pilus, non-pilus
adhesions, exoenzymes and secretory
virulence factors like elastase, protease,
phospolipase, pyocyanin, exozyme S,
exotoxin A, hemolysins and siderophores
Pseudomonas also shows tendency to form
biofilms on the surface of urinary catheters in addition to these virulence factors.13
The risk of UTI increase with duration of catheterization and the Acute Nosocomial UTI
is usually asymptomatic7 CA-UTI induced signs and symptoms include new onset of worsening of fever, rigors, malaise or lethargy, with no other identified cause, altered mental status, flank pain, tenderness of the costo- vertebral angle, acute hematuria, pelvic discomfort, and dysuria, urgent or frequent urination, or suprapubic pain or tenderness in those whose catheters have been removed.10 In patients with spinal cord injury (SCI), increased spasticity, autonomic dysreflexia or sense of unease are also compatible with CA-UTI.9
Although recommendations have been made
to treat CAUTI’s only when they are
symptoms have not been clearly defined and unrelated to CAUTI, the presence of an indwelling urinary catheter alone can cause dysuria or urgency.16
Materials and Methods
On approval from ethical committee, in our study 100 in-patients of Intensive care units were analysed for a period of 1 year from December 2012 to November 2013 in Microbiology department at Sree Gokulam Medical College and Research Foundation The sample included admitted Patients with indwelling catheter of either sex and above 19 years of age of all intensive care units of Sree Gokulam Medical College and Research Foundation The samples of Patients with confirmed urinary tract infection before catheterization, patients whose lab culture
Trang 4reported as mixed flora, Urinary catheter tips,
Urine from catheter bagswere excluded
Samples of urine after insertion of catheters
will be collected aseptically within 2 hours
from the time of insertion for baseline urine
cultures and microscopic examination
Thereafter urine cultures and urine analysis
will be done on the 3rd day, 5th day, 7th, until
Catheter is removed or significant bacteriuria
occurred on two consecutive cultures or
patient is discharged, whichever comes early
Minimum three samples will be collected from
each individual Urine samples will be
collected by aspirating urine from the Foley’s
catheter with sterile syringe with gauge 26
needle after disinfecting the catheter with 70%
alcohol
The samples are transported to the
Microbiology laboratory immediately If there
is a delay of >2 hours, sample is refrigerated at
4oC9 Wet film microscopy and urine cultures
will be done
A colony count of ≥ 103 CFU/ml is considered
positive All the isolates were identified by
standard procedures and biochemical tests and
antimicrobial susceptibility test was done for
pathogens isolated, by Kirby-Bauer disc
diffusion technique
The antibiotic discs used were from Himedia
and the discs used were Ampicillin (10µg)
Amoxyclav (20/30µg), Cephalexin (30µg),
Cefuroxime (30µg), Ceftazidime (30µg),
Cefotaxime (30µg), Cefipime (30µg),
Gentamicin 10µg), Netilmicin (30µg),
(1.24/23.75µg) Nitrofurantoin (300µg),
Ciprofloxacin (5µg), Norfloxacin (10µg),
Ofloxacin (10µg), Tetracycline (30µg),
Piperacillin (100µg), Aztreonam (30µg),
Cefoperazone Sulbactam, Piperacillin
Tazobactam (100/10µg), Imipemen (10µg),
Meropenem (10µg) Colistin (10µg), Cefoxitin
The antibiotic susceptibility was interpreted as sensitive, intermediate or resistant by comparing the observed zone of inhibition of the test organisms to the required zone size for the Standard strains as per CLSI Guidelines
Results and Discussion
The results obtained are as follows:
Out of 100 samples collected, 56 samples were collected from MICU, 24 from SICU, 12 from NSICU, 7 from POICU and 1 from CCU respectively
Total numbers of samples collected in the study were 100 Among them 45 samples were from male patients and 55 samples were from female patients
Among 100 samples collected 26 samples were culture positive showing growth, 74 samples were culture negative showing no growth
Total number of patients catheterized for one week were 43, and the growth observed among this 43 was 3.Total number of patients who were catheterized for upto two weeks was
36, among the 36 growth observed was 6 Out
of the 15 patients catheterized for up to 3 weeks growth observed was 11 and 6 patients catheterized for ≥ 4 weeks all of them developed CA-UTI
Out of the 26 culture positive samples, 15(57%) were from MICU, 4(15%) were from SICU, 3 (11%) were from NSICU, 2 (7%) were from POICU and CCU The highest percentage of growth was found in Medical ICU
Out of 45 samples collected from males 18 (40%) were culture positive Out of the 55 samples collected from females 8 (14.5%) were culture positive
Trang 5Out of the 26 gram negative bacilli isolated,
11 (42.3%) were E coli, 5 (19.2%) were
Klebsiella pneumoniae, 5 (19.2%) were
Pseudomonas aeruginosa, 2 (7.7%) were
Citrobacter freundi and 1 (3.8%) each of
Enterobacter cloacae, Acinetobacter spp,
Schewanella algae respectively
Percentage of E coli isolated in our study
was18.3% E coli showed highest rate of
sensitivity to Imipenem (100%), lowest rate of
sensitivity to Cephalosporins (27.3%) and
Ampicillin (27.3%), and moderate rate of
sensitivity to Aminoglycosides [Ak (63.6%),
Gen (45.5%), Net (45.5%) respectively] and
Fluoroquinolones (36.4%) About 54.5% were
sensitive to Tetracycline and 72.7% were
sensitive to Cefoperazone –Sulbactam and
Piperacillin –Tazobactam
Klebsiella Spp showed 100% sensitivity to
Sulbactam, and Piperacillin- Tazobactam
None were sensitive to Ampicillin (0%) It
showed 40% sensitivity to Piperacillin,
Amoxycillin-Clavalunic acid, Cephlexin,
Cefuroxime, Ceftazidime, Cefotaxime,
Cefipime, Aztreonam and Nitrofurantoin
Sensitivity to Tetracycline and Cotrimoxazole
were 60% Only 20% were sensitive to
Fluoroquinolones
The next predominant pathogen Citrobacter
freundi isolated were 2 in number (3.3%),
Citrobacter freundii isolated showed 100%
resistance to Ampicillin,
Amoxycillin-Clavalunic acid, Cephalexin and Cefuroxime
50 % sensitivity was observed towards
Cefotaxim, Ceftazidime and Cefipime,
Fluoroquinolones and Tetracycline No
resistance was shown to Cefoxitine, and it was
found to be 100% sensitive to Nitrofurantoin,
Cotrimoxazole, Cefoperazone-Sulbactam,
Meropenem
resistance to Piperacillin, Ceftazidime and Cefipime It also showed 100% resistance to Fluoroquinolones and Aminoglycosides like
Pseudomonas was sensitive to Tobramycin and Piperacillin-Tazobactam (40%) 100%
Meropenem and Colistin
Only one Acinetobacter was isolated, It was a
multidrug resistant strain, It showed complete resistance to all tested antibiotics except to Aztreonam, Imipenem, Meropenem and Colistin
Among the 26 uropathogens only one
Enterobacter cloacae was isolated The isolate
Piperacillin-Tazobactam, Cefoperazone-Sulbactam, and Carbapenems
Lastly among the Gram negative bacilli one
rare uropathogen Schewanella algae (1) was
isolated It was found to be sensitive to Nitrofurantoin, Cotrimoxazole, Ceftazadime,
Aminoglycosides, Piperacillin Piperacillin-Tazobactam, Cefoperazone-Sulbactam, and Carbapenems
In our study the percentage of ESBL among
the E coli was 36.4% and in Klebsiella,
Citrobacter and they were 75%, and 50%
respectively No ESBL production was
observed in Enterobacter Amp C production for E coli, was 18.2%, whereas there was no Amp C production in Klebsiella and
Citrobacter
Urinary tract infections (UTIs) are commonly acquired in hospitals, representing 30% -40%
of all nosocomial infections with an estimated prevalence of 1% to 10%.12
Trang 6.Catheter-associated urinary tract infections is the most
common nosocomial infection and accounts
for bacteremia in 2 to 4% of patients and the
case fatality associated with it is three times as
high as nonbacteriuric patients.15 All age
groups are affected by UTI and are diagnosed
in both outpatients and hospitalized patients It
causes a serious burden on the socio economic
life of individuals and leads to consumption of
large population of all antibacterial drugs used
in the world6 Among catheterized patients the
reported incidence of CAUTI ranges from as
low as 5% to as high as 73%.4 In the present
study, out of 100 cases studied, 26 %
developed CAUTI and high incidence of
CAUTI was found in the first two weeks of
catheterization This result is comparable with
that of a study by Danchaivijitr et al., 7where
one hundred and one patients met the
inclusion criteria and the incidence of CAUTI
was 73.3% and high incidence of CAUTI was
found in the first two weeks of catheterization
None of the episodes of CAUTI in our study
was associated with nosocomial bacteremia
and prolonged catheterization was identified
as a risk factor in the present study, also
similar to the study by Danchaivijitr et al.,7
In most of the Indian studies and studies from
abroad the most common organism was E
our study was E coli [18.3%] This is in
agreement with study by Danchaivijitr et al., 3
in 101 catheterized patients where E coli
(15.1%) isolated Whereas in an Indian study
conducted by Manish et al., 10 in 100 adult
patients with an indwelling Foleys catheter the
most common organism colonizing and
causing catheter associated urinary tract
infection was found to be E coli (57%)
The percentage of Pseudomonas aeruginosa
isolated in the present study was 8.3% Other
studies isolated Pseudomonas aeruginosa in
the range of 2% 16 to 20.6%11, whereas in a
study by Dutta et al., the commonest organism
Pseudomonas aeruginosa
Klebsiella pneumoniae (8.3%), Citrobacter freundii (3.3%), Acinetobacter (1.7%) spp, Enterobacter cloacae (1.7%), Shewanella algae (1.7%) were the other uropathogens
isolated in that order in our study
Contrary to other studies in which CAUTI was prevalent in females in our study CAUTI was more prevalent in men Out of 45 samples collected from males 18(40%) were culture positive Out of the 55 samples collected from females 8 (14.5%) were culture positive Bacteria, which exist as a biofilm inside catheters, show higher antimicrobial resistance when compared to non-CAUTI pathogens6 In
the present study E coli showed highest rate
of sensitivity to Imipenem (100%), lowest rate
of sensitivity to Cephalosporins(27.3%) and Ampicillin(27.3%), and moderate rate of sensitivity to Aminoglycosides [Ak (63.6%), Gen (45.5%), Net (45.5%) respectively] and Fluoroquinolones (36.4%) About 54.5% were sensitive to Tetracycline and 72.7% were sensitive to Cefoperazone–Sulbactam and Piperacillin–Tazobactam
Klebsiella pneumoniae isolated in our study is
8.3% The other less predominant pathogens
isolated in our study were Citrobacter freundi
Enterobacter cloacae (1.7%) and Shewanella alga (1.7%)
In our study out of the lesser common
pathogens isolated Citrobacter freundii was
3.3% that is out of the 60 uropathogens only 2 were Citrobacter freundii A similar observation was found in a study by Aravind
in which 1 Citobacter freundii was isolated
among the five uropathogens causing CAUTI.19 In our study C freundii showed
Trang 7100% resistance to Amoicillin, Amoxycillin-
Clavalunic acid, Cephalosporins and 100%
sensitivity to Nitrofurantoin, Cotrimoxazole,
Cefoperazone-Sulbactam,
Piperacillin-Tazobactam, Imipenem and Meropenem, We
could not compare the sensitivity pattern with
as other studies which reported their
sensitivity pattern were rare In our study out
of the sixty uropathogens isolated only one
Acinetobacter was isolated, It was a multidrug
resistant strain and it showed resistance to
Aminoglycosides, Piperacillin, Aztreonam and
Piperacillin-Tazobactam whereas it showed
sensitivity to Imipenem, Meropenem and
Colistin Similar to our study only 1%
Acinetobacter was isolated in a study by
Chaudhary et al., and it was a strain sensitive
to Amikacin alone.10
The rare pathogen isolated in our study i.e
Shewanella alage, which was a sensitive strain
showing sensitivity to all the antibiotics used
in the study In our study among Gram negative fermenters the highest number of
ESBL and Amp C producers belonged to E
coli (ESBL: 36.4%, AmpC: 18.2% followed
by Klebsiella (ESBL: 75%, AmpC: 0%) Patil
et al., in his study observed that the percentage
of ESBL production in E coli causing UTI in
patients with indwelling catheter was 20.68%
and in Klebsiella it was 43.75%.20 Several studies have reported the incidence of ESBL among pathogens causing urinary tract infections and it ranges from 34.8% to 64.2%21, 22, 23 According to a study conducted
by Talaat et al., on surveillance of
catheter-associated urinary tract infections in 4 intensive care units at Alexandra university hospitals in Egypt, The prevalence of ESBL
producers among K pneumoniae and E coli
isolates was 56% and 78.6% respectively (Table 1-10)
Table.1 Number of samples obtained from the various ICU’s
Table.2 Sex wise distribution
Table.3 Samples showing growth
Trang 8Table.4 Association between the duration of catheterization and catheter- associated urinary tract
infection
Duration of Catheterization Total no: of patients
catheterized
Growth seen
Pearson ChiSquare value: 32.47, p value< 0.001
Table.5 Percentage prevalence of catheter-associated urinary tract infections in the various ICUs
of a tertiary care hospital
Table.6 Sex wise distribution of positive cultures
Pearson Chi Square value: 4.209, p < 0.05
Table.7 Gram negative bacilli isolated
Trang 9Table.8 Antibiotic susceptibility pattern of E coli, Klebsiella pneumoniae
and Citrobacter freundii
Escherichia coli
(n=11)
Klebsiella pneumoniae
(n=5)
C.freundii
(n=2)
Table.9 Percentage of ESBL and AMPc among Enterobactericiae in the various ICU’s
Trang 10Table.10 Antibiotic susceptibility pattern of Pseudomonas aeruginosa and Acinetobacter species
isolated
Pseudomonas aeruginosa
(n=5)
Acinetobacter spp (n=1)
In conclusion, all health care associated UTI
are caused by instrumentation of the urinary
tract The incidence of CAUTI in the present
study was 26%.The incidence was more in
males and risk factors identified were
prolonged catheterisation, old age and
diabetes mellitus
High incidence of CAUTI was found in the
first 2 weeks of catheterisation Longer
duration of catheterization increases the
chances of CAUTI
The most common organism associated was
E coli [18.3%] and Pseudomonas aeruginosa
[8.3%], Klebsiella spp (8.3%) Hospital
acquired CAUTI is often due to multi drug
resistant strains which require higher
antibiotics and these strains may spread to
other patients Gram negative organism
showed high degree of sensitivity to
Cefoperazone-Sulbactam,
Piperacillin-Tazobactam, Carbapenems, and Colistin whereas high resistance was observed for Ampicillin, Amoxycillin-Clavalunic acid, Cephalosporins, Aminoglycosides and Fluoroquinolones and moderate sensitivity
Cotrimoxazole and Tetracyclines The antimicrobial susceptibility pattern confirmed that most of the urinary isolates in our environment are resistant to the commonly used antibiotics including cephalosporins and fluoroquinolones Effective infection prevention measures should be in place to reduce the prevalence of nosocomial UTIs Better management of urinary catheter is to be explored and implemented
References
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DO, Turan G, Ceran N, et al.,
Alterations in Bacterial Spectrum and